Welding method for double bevel groove (DHV) weld joints

Abstract

The invention provides a welding method for double bevel groove (DHV) weld joints. The method is applied to a single welding workpiece. The bevel of the first side weld joint of the single workpiece is not symmetrical to the bevel of the second side weld joint of the single workpiece; the angle of the bevel of the first side weld joint is smaller than the angle of the bevel of the second side weld joint; and the depth of the bevel of the first side weld joint is larger than the depth of the bevel of the second side weld joint. The method comprises the steps that the first side weld joint is welded, wherein the angle of the bevel of the first side weld joint is larger than or equal to 50 degrees, and is smaller than or equal to 60 degrees; after the first side weld joint is welded, back gouging and back gouging penetration testing are performed on the second side weld joint; and after back gouging penetration testing is passed, the second weld joint subjected to back gouging is welded. According to the welding method for the DHV weld joints provided by the embodiment of the invention, the back gouging quality and the welding quality can be effectively ensured.

Description

technical field [0001] Embodiments of the present invention relate to welding technology, in particular to a welding method for double-sided bevel butt (Double bevel butt, Double HV, DHV for short) type welds. Background technique [0002] In subway rail vehicles, DHV type welds are generally used for assembly and welding between the coupler panel, the upper cover and the lower cover. [0003] At present, the commonly used DHV type welds are mostly double-sided symmetrical weld structures. figure 1 It is a structural schematic diagram of a DHV weld seam in the prior art. Such as figure 1 As shown, the weld structure between the coupler face plate 1 and the upper cover plate 3 is a symmetrical DHV type, that is, the groove angles of the weld seam 2 and the weld seam 4 are equal. For example, if the thickness of the coupler face plate t=25mm, the corresponding weld Seam 2 and weld 4 are 12.5HV / 12.5HV, blunt side p=1mm, then the groove angle on both sides is α=60°. When wel...

AI Technical Summary

Problems solved by technology

[0005] 1. When cleaning the root, because the groove angle of the weld on the cleaning side is small, the accessibility of the straight grinder is limited, resulting in incomplete cleaning between the weld layers, leaving impurities inside the weld, resulting in re- Welding defects such as lack of fusion between layers are prone to occur during welding

[0006] 2. The groove angle of the weld seam after root cleaning is smaller, which cannot meet the requirements of the EN15085-3 standard that the groove angle of the weld seam is within the range of 50°-60°, which makes the welding arc more difficult Contacting the root of the groove and the upper surface of the groove, therefore, it is easy to produce no fusion at the root of the weld and the upper surface of the weld, and the welding residual stress is unevenly distributed, resulting in poor weld quality and reduced weld strength

[0007] Therefore, the DHV type weld seam welding process of the prior art cannot effectively guarantee the quality of root cleaning and the welding quality after root cleaning

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